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1.
Introduction
Percutaneous nephrolithotomy (PCNL) is the standard of
care for the management of large renal stones greater than
2 cm in size
[1]. Contemporary multi-institutional registry
data demonstrates that stone-free rates (SFR) for nonstag-
horn and staghorn stones treated with PCNL range from 77%
to 83%, and 33% to 57%, respectively
[2,3] .Common
complications from PCNL include postoperative fever
(8.7–14.8%), bleeding (7.8%), sepsis (0.9-4.7%), blood
transfusion (5–18%), and hydrothorax (2%)
[2,4–6]. Recent
studies have revealed that retreatment rates after PCNL can
be as high as 30–40% in patients with residual fragments
(RF)
[7,8] .Open nephrolithotomy may be considered when the
stone cannot be removed by a reasonable number of less
invasive procedures. Patients in this group include those
with extremely large staghorn calculi, unfavorable collect-
ing system anatomy, extreme morbid obesity, and skeletal
abnormalities
[9]. However, open surgery is rarely per-
formed for stones in the modern era, and instead
laparoscopic approaches are utilized as alternatives to
PCNL. In a meta-analysis comparing laparoscopic pyelo-
lithotomy with PCNL, laparoscopy had significantly lower
rates of bleeding and sepsis, as well as a trend towards a
higher SFR
[10] .More recently, robotic pyelolithotomy
(RPL) and robotic nephrolithotomy (RNL) have been shown
to be safe and feasible options for removing large renal
stones in toto as a single specimen, without stone
fragmentation
[11–13]. Compared with a pure laparoscopic
approach, RPL and RNL may have advantages of improved
dexterity for suturing and reconstruction. With robotics or
laparoscopy, the lack of fragmentation limits the risk of RFs,
and may have long-term benefits in avoiding surgical
retreatment.
Previous reports of RPL and RNL have been limited to
small studies from single institutions
[3,12,13]. The
purpose of our study is to evaluate patient outcome data
for RPL and RNL from a multi-center collaborative of
robotic surgeons, and evaluate its efficacy and safety. We
also describe the technique with an accompanying video
in this article, including tips and tricks for successful
surgery.
2.
Material and methods
We performed a retrospective review in five surgical centers performing
robotic renal surgery for stone disease (Ann Arbor Veterans Affairs
Hospital, Ann Arbor, MI, USA; Wake Forest Baptist Hospital, Salem, NC,
USA; Henry Ford Health System, Detroit, MI, USA; Medical College of
Georgia, Augusta, GA, USA; Mount Sinai Hospital, New York, NY, USA).
The institutional review boards of all centers approved retrospective
data collection; data were collected on 27 patients undergoing RPL and
RNL performed by K.R.G., R.M., A.H, J.S.E., and K.B. from 2008 to
2014. Only procedures without the use of renal ischemia were included
in this series. Patients with intrarenal pelvis are not suitable for RPL, and
were excluded for surgical consideration. One center from our group has
already published results of robotic anatrophic nephrolithotomy using
renal ischemia, and are not included in this series
[12] .Procedures were
performed using either a transperitoneal or retroperitoneal approach.
The approach was based on surgeon preference or stone location.
Posterior stones are suitable for a retroperitoneal approach.
2.1.
Surgical technique
2.1.1.
Patient preparation
Patients undergoing transperitoneal RPL were instructed to be on a clear
liquid diet the day prior to surgery. No bowel preparation was needed for
retroperitoneal surgery. All patients received a preoperative type and
screen.
2.1.2.
Patient positioning
Procedures performed transperitoneally utilized a standard robotic
approach for kidney surgery. Patients were positioned in the lateral
decubitus position with the affected side up. For the retroperitoneal
approach, the patient is placed in the full flank position with the table fully
flexed to increase the space between the 12th rib and iliac crest. The spine
and hip is positioned in a straight line. In both approaches, the dependent
arm is padded and secured to an armrest, which is tilted towards the head
as much as possible to avoid clashing with the robotic arms.
2.1.3.
Port placement
Transperitoneal:
A 12-mm camera port is placed lateral and superior to
the umbilicus and three 8-mm robotic working ports were placed under
direct vision in the ipsilateral upper quadrant, lower quadrant, and
lateral abdomen. A 12-mm assistant port is usually placed close to the
midline, midway between the camera port and the robotic ports. Some
centers used a fourth robotic armport to aid with retraction of the kidney
and exposure of the renal pelvis and hilum.
Retroperitoneal:
The camera port is placed above the iliac crest, lateral
to the triangle of Petit. A 12-mm incision is made in this area, and the
lumbodorsal fascia pierced to enter the retroperitoneal space. A balloon-
dilating device (OMSPDBS2; Covidien, Mansfield, MA, USA) is inserted
and expanded under direct vision using a 30
8
laparoscope. This is
swapped for a 12-mm camera port for the robotic camera. Two 8-mm
robotic ports are inserted, the first being above the erector spinae
muscles just under the 12th rib, and the second port 7–8 cm superior and
medial to the camera port. A 12-mm assistant port is placed in the
anterior axillary line cephalad to the anterior superior iliac spine, and 7–
8 cm caudal to the medial robotic port.
2.1.4.
Docking
For transperitoneal surgery, the patient side-cart is docked in a 30–45
8
angle from the flank as per standard for robotic renal surgery. For
retroperitoneal surgery, the side-cart is docked over the patient’s head
parallel to the spine.
2.1.5.
Instruments
Robotic instruments include monopolar shears, monopolar hook, bipolar
fenestrated grasper, Prograsp forceps, and needle drivers. We also
recommend use of a robotic ultrasound probe (Hitachi Aloka, Wall-
ingford, CT, USA) and availability of a flexible nephroscope.
2.1.6.
Surgical dissection
Transperitoneal:
The kidney is mobilized and the renal hilum exposed in a
similar fashion as for robot-assisted partial nephrectomy. While we do
not clamp the vessels, it is important to have the renal vessels exposed in
case of the need to clamp due to excessive bleeding at the time of the
nephrotomy incision. After hilar dissection, the renal pelvis is dissected
and mobilized being careful to protect the upper ureter and avoid
excessive mobilization.
Retroperitoneal:
The Gerota’s fascia is incised just above the psoas
muscle, exposing the perinephric fat and the kidney. Dissection is then
carried out along the psoas muscle, elevating the kidney and perinephric
fat until the hilum and renal pelvis is encountered.
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